Going from OA3 to OB3, OC3, and OD3 will progressively chill the bass and open the sound?

From Deckware page on the TORII MKIII -

"The voltage regulating tubes can also be changed to effect the bias and sound of each different output tube. You can use an OA3 which gives the highest grid voltage and usually the most low end performance. You can use an OD3 which gives the lowest grid voltage and usually the tightest bass. If you wished it to land somewhere in between, there is the OB3 and OC3."

"Within the tonal variation depending on vintage and construction, the OA3 will push the power tubes the hardest, giving you the most sense of push and density. If you would prefer a slightly leaner, less driving sound, the OB3 is a valid adjustment to provide that. And progressively the OC3 and OD3 will open things up more and reduce density."

"The OC2 to OB2 has a similar effect, but on the input tubes. In my big torii going to and OB2 sounds cool, but finally to me has too much effect for leaning things up, but it all depends what you want and where you are starting from sound-wise."

"If you have too much density overall, or the low to mid-bass is too dense and heavy, or if your sound feels a bit in your face, depending on how much change you want, trying an OB3, OC3, may be worth it."

"Assuming we could start with similarly toned OA3s, OB3, OC3, and OD3s...and if the OA3 makes the amp a little dense and bassy in a system/room, masking the mids, upper mids, and highs a bit, you can definitely enhance the sound stage and clarity with an OB3, OC3, or OD3, each progressively "de-saturating" the sound more. The players generally stay in the same soundstage postion, but the "meat" of each instrument is chilled a bit, leaving the rest of the presentation aspects more space. The mids and upper mids awaken a bit as the low-mids and bass chill a bit. Ambient information takes more space in the sound. The instruments themselves became a bit more spacious and clear, but also the space around them."

"The rest will depend on the sound you want to get, as stated earlier (from OA3, OB3, OC3 to OD3 output voltage regulators, for example), and OA2 (VR150) as opposed to OC2 (VR75) in the input voltage regulation, all these possible combinations giving you choices in terms of warmth vs transparency and bass profiles with the output regulation, gain modifications with the input regulation."

"Forgot the OC2. I usually leave in the Raythion (richer) but for some tube sets the RCA (cleaner). But a OB2...that will really open things up if you need it....similar to the OA3, OB2 etc. but in this case the reg is before the input I believe."

"or example, different coke bottle OA3s, or different straight side OA3s can make a big difference toward fine tuning. And generally there is a difference between those shapes. Then with regulators, you can get into OB3, OC3, OD3, most of which sound different for the reasons above, but also each of them offer different voltages that effect the power tubes differently, so can really shift the sound."

"So I am glad you have and OD3 to play with...It is likely to lean down the sound a fair bit over the OA3 and give you a good sense of what can be done with the OB3 and OC3 who's voltage is between these two. The slight variation in your Rectifiers might be a great tool too for tuning a tube set....one perhaps a bit bigger and pushier and one a little more low key all else being equal (unlikely)."

Of course, the new DAC makes a big improvement, as the tendency to hide some details when going for the smooth Black Plate drivers is gone with the ESS 9018 chip in that DAC. I'm getting fine detail and a larger soundstage, ceteris paribus, on 24/192, 24/96 and 24/44.1 recordings.

The only thing I'm missing is a little more 'oomph'! As it is, it is enough for most of my needs, but sometimes I could use more of it. I wonder if adding the CSP3 would bring about some more oomph'?